Building A Set Of Doubles

Building A Set Of Doubles
Doubling up a set of cylinders is not difficult, however it can be time consuming. In this video, Instructor Bryan Stafford and Divemaster Troy Miller show us how to take two single aluminum cylinders and double them up with a manifold and set of bands.
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Lake Hickory Scuba Center & Marina
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[@IncendiaHL]

9:11 "DEEZ NUTS!!"

[@LakeHickoryScuba]

Way to much time on your hands. LOL

[@deepdiversi5913]

Awesome lads, a lot of info packed into a short video-love it

[@LakeHickoryScuba]

Hello DeepDiverSi, glad you liked the video.

[@rgorji]

This is an excellent video. It goes over all the little important points that are sometime subtle. THANK YOU.

[@LakeHickoryScuba]

You’re welcome, glad you like our video.

[@HumbledExplorer]

Very informative!! Thanks for sharing!

[@LakeHickoryScuba]

Glad you liked the video HumbledExplorer

[@divingmadd6219]

Great Video

[@LakeHickoryScuba]

Thank You, glad you liked it

[@BurhanMuntasser]

Good Job!

[@LakeHickoryScuba]

Thank You.

[@timgosling6189]

Another great video. All I'd say is I put the bands loosely on the cylinders while I'm adjusting the manifold to make sure the spacing is going to be right when I tighten it off. Sometimes the bands impose a spacing that's requires the manifold to be not all the way screwed in when you lock it off.

[@LakeHickoryScuba]

Very true and thanks for pointing that out Tim Gosling.

[@never2old-sd638]

Nice, I’m thinking myself to get a back plate for a set of doubles 🤙

[@LakeHickoryScuba]

Thank you glad you liked the video. Make sure to check out several of our Back Plate and Wing videos for reference.

[@flhrci1]

Really could have used this video in 2003 when I set up my first set. :) Would have saved me a lot of frustration. Still use that same set though.

[@LakeHickoryScuba]

Hello flhrci1, glad you found our video helpful.

[@JMLockpicking]

Nice one.

[@LakeHickoryScuba]

Thank You

[@michaelanthony7484]

Hi really great video! Name is michael and I live in Ireland. I have in mind to buy two 6.8 L Carbon Fiber/AL tanks out of Europe (Poland) to keep taxes manageable. I used to dive a now very, very old 2250psi 72. I'm also buying a high quality dive compressor. While I still have the aforementioned US Divers tank with a J valve, there is no way I would try even a lb in it. It's well beyond sell-by.! (Before someone in Ca. conned me out of it, I also had at one time a double hose Royal Aquamaster regulator that went with it. Spilled milk! Mind you, the interior remains pristine, totally immaculate (US Divers for you). Your video answered most all questions save one...and I feel like a dummy for asking, but I note each tank retains it's customary regu;lator port plus O ring on each valve connected to the main one mid manifold. May I assume one would shut off one of the individual valves on one side and attach the regulator to the other? Can't actually see any other way, but you're the expert, so therefore the right man to ask. To demonstrate my ancient lineage, I am Naui open water, never bothered with Padi. Back in those days, the final was a real bitch, but having dived (mainly while in Aruba) since age 14, with Heaven's help I thankfully managed. Cheers! [e-mail] Thanks!!

[@LakeHickoryScuba]

Hello michael anthony, I am not totally confident I understand your question completely, but I will try my best to answer it. If you are asking if you can just attach one regulator to the cylinder and still get air from both cylinders, then yes you can. However, you will defeat the purpose of a manifolded valve. The sole purpose of the manifolded valve is redundancy. If one post malfunctions, then it can be shut down, and the air can still be accessible from the other regulator. In the event one side fails, it can be closed off via the isolator valve in the middle, preventing a total air loss. On a side note, you mentioned the Carbon Fiber tank, those are not that popular here in the States, as their buoyancy characteristics are very positive. Most divers have to compensate by adding way too much weight. Depending on the size of the cylinder, they may work great for redundant air systems, but not so much for primary systems. Hope this answer your questions, if not please do not hesitate to send us an email. [e-mail]

[@charlesclements4350]

Good thing putting out this video because I did not know that you existed. You do a very good job of instructing. Are you going to do a video about your marina? I would be interested in knowing what amenities you have.

[@LakeHickoryScuba]

Hello Charles Clements, we would be happy to do a video about our marina.

[@charlesclements4350]

Great! I am waiting.

[@soundscuba1639]

Great video Bryan. Is there a special o-ring lube if the doubles are to be used with nitrox?

[@LakeHickoryScuba]

We use O2 compatible silicone and cristo-lube for cylinders if they are going to be used for nitrox diving.

[@timgosling6189]

@@LakeHickoryScuba No point in having all that gas if you run out of NDL :-)

[@SierraNovember3]

09:12

[@LakeHickoryScuba]

Yes sir.

[@rickkinney2544]

So the first stage will connect to one of the tank valves - does it matter which one? I'm used to seeing the first stage centered between the tanks.

[@LakeHickoryScuba]

When you dive a set of doubles, you have two first stages, one on each post. We are going to be doing more double videos in the future.

[@mochammadfadly6905]

Bryan! When seting doble tank for mares pure sls, bolt and hyibrib pro tec... What same?

[@LakeHickoryScuba]

Hello Mochammad Fadly, I'm not sure I quite understand your question, but here is a video we did showing you how to attach the Mares Pure SLS to a set of doubles. kzbin.info/www/bejne/gGq5Z2ODdsmFoqs

[@999racing]

One little thing, the measuring band is alright, it's on purpose that the metal thing at the end moves and it moves exactly the amount that the metal is thick so that if you hold it on and pull it it shows the same as if you push it against it 😉

[@LakeHickoryScuba]

You would be correct.

[@ivoryjohnson4662]

That's my goal to get to tech

[@LakeHickoryScuba]

Set a goal, strive for it, reach it, then set another one. We should never stop learning.

[@leobritton8929]

" Tighten down on deez nuts!"

[@LakeHickoryScuba]

Glad you picked up some useful information from our video Leon Britton.

[@diversdown2116]

how long are the bolts and are the same for 7.25 & 8 inch

[@LakeHickoryScuba]

The ones used in this video are 5 inches in length. If you are trying to band together with 8 inch bands, then you will need 5.5 inch bolts.

[@jhkleinberg2]

When running aluminum 80s. When at 500psi they could very well be - 4 to 6 pounds depending on manufacturer. Do you ever add weight to make them neutrally buoyant?

[@LakeHickoryScuba]

Hello Joe kle, I am fortunate enough that my weight is always balanced out no matter what gear I wear. Especially in a 3 mm wetsuit. So typically I do not have to add extra weight to the cylinders. Not all divers can say this, and it is not uncommon to see divers do this.

[@gdolloway]

Isn't there trouble with the buoyancy variances between cylinder brands and cylinders manufacturing tolerances between batches?

[@LakeHickoryScuba]

Great question. If so it’s on such a minor scale, there is hardly any noticeable difference.

[@charlesg7926]

I agree with LakeHickoryScuba. That’s a really minor difference, it would be like splitting hairs. The key is just following good buoyancy fundamentals: know your body, know your wetsuit (or drysuit), know your BC, know your equipment. You should be able to (slowly) descend with your BC empty and lungs empty, at surface, but able to stay at eye level to the top of water, with lungs full. Don’t be over weighted. If your choice of weighting is correct, then you’ll be fine regardless of the cylinder. Worst case if you can’t get down, just add a pound or 1/2 kg or so. And as you’re diving, and your tank gets lighter, just squeeze more air out of your BCD, especially when you’re re-ascending (you’re generally able to squeeze a little more out). And breathing control. For me, I’m able to just use 8 pounds with a DRYSUIT and TUSA BCD, in ocean water, with a single steel tank.

[@daviddemerly7919]

Hey did you know the tape is designed to move to compensate for the lip based on weather your pushing or pulling if the lip didnt move it would throw the reading off

[@LakeHickoryScuba]

Hello David, I sure did.

[@gerryyeager5605]

Is there a preferred size of tank to run doubles?

[@LakeHickoryScuba]

Hello Gerry Yeager, it all depends on a diver's needs and his physical attributes. Back when I did dive doubles, I preferred high pressure steel 100's. A lot of divers who are taller or will typically dive in colder environments, where their weighting needs are greater will dive larger cylinders. Some divers prefer low pressure 85's and 95's, because of the possibility of plus rating fills.

[@IncendiaHL]

Something I don’t understand. I’m about to take my PADI open water and advanced cert. Only thing is, I think I would prefer to dive Hogarthian with twins. Can I go buy and dive such a setup after padi certification?

[@LakeHickoryScuba]

Hello IncendiaHL, you most certainly can dive doubles and a Hogarthian setup after your certification. I would suggest to you to ask your Instructor to run through some valve drills with you so that you know how to handle a situation with the doubles if they were to occur. Safety First.

[@IncendiaHL]

Thanks man! Love your channel! :)

[@LakeHickoryScuba]

You're welcome

[@charlesg7926]

Legally yes, you can dive twins as long as you’re certified. (Actually legally, I don’t even think it’s a USA law to be certified to dive at all; although it is a law in most of Europe). However, if you aren’t trained for doubles or Tech diving, many dive boats will be hesitant to let you dive with them, and some shops may refuse to sell you them for liability reasons. But you can always bribe places and offer to pay extra if they don’t ask questions. In general I recommend first getting your “deep dive” cert, and then “intro to tech” + “twinset (aka doubles)” certifications. Diving doubles can be tricky, especially in terms of weight, balance, and setup and they can be especially risky if you’re mixing gases and going deeper than Rec limits before you’ve been trained for that Good documentary to watch, “Monty’s dive mysteries: Blue Hole” best 45 minutes you’ll ever see on diving and really eye opening

[@SierraNovember3]

I had a shop assemble my tiny doubles (LP50’s) and noticed that my top band has space bilaterally on the inner circular portions of the bands. The bottom band fits like a glove with no space between the band and tanks. Both bands are sized appropriately for the tank’s circumference. Is it safe to loosen the top band and spin the manifold to tighten/bring the top portion of the tanks together to take the space out of the top bands after they’ve been filled? Or would I need to bleed off all the gas first?

[@LakeHickoryScuba]

Hello @SierraNovembera3. You can most certainly adjust the bands and the isolator on your own. Just make sure you are not putting to much tension on the system and you should be just fine.

[@benjaminsmith7024]

Dese nuts !

[@LakeHickoryScuba]

Hello Benjamin Smith, glad to know you got something from this video.

[@scubacro5758]

Is it normal that you can not turn manifold while tanks are full ? I can't move it even when I loosen my bands

[@LakeHickoryScuba]

Hello @scubacro5758, a little bit of movement is ok, but it should have tension to it. Once you lock down your set nuts, it should not move.

[@jasonbatson2363]

So is a twin 80 with a 40 emergency tank to much?

[@LakeHickoryScuba]

Hello Jason Batson, it all depends on your personal needs. I have a set of twin 80's (steel's), which will be featured in an upcoming video. I use them for a very specific purpose. If you need them and you are comfortable diving with them, and if you have been trained to use doubles, then I say go for it.

[@timchen7424]

9:12 ;)

[@LakeHickoryScuba]

Hello tim chen, thank you for noticing.

[@SquigglyCarton8]

Why do Americans love AL80’s so much? Steel is so much better and is the national standard here in Australia

[@LakeHickoryScuba]

Hello SquigglyCarton8, I'm not sure I can answer that question for all Americans. It would make a great poll question though for you to put out there to see what kind of answers you may get.

[@superbholidays3520]

Great video but it would have been Superb to respray the tanks before rebuild 👍

[@LakeHickoryScuba]

Very true.